We have investigated the effect of an external magnetic field on the angular distribution and the linear
polarization of the 2s22p53s 3Po
2
→ 2s22p6 1S0 emission line in Ne-like ions. Since an electric dipole decay
channel is opened by the magnetic field and competes with the inherent magnetic quadrupole transition, these
properties strongly depend on the magnetic field strength, B. As an example, we discuss in some detail this
transition in neonlike magnesium. This is of special interest, since the B-dependent angular distributions and
linear polarization degrees are potentially unique diagnostic tools for the magnetic field in different plasmas.